From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 148C7C31E5B for ; Mon, 17 Jun 2019 17:40:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DBD432084D for ; Mon, 17 Jun 2019 17:40:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="O5FVqlkb" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728602AbfFQRke (ORCPT ); Mon, 17 Jun 2019 13:40:34 -0400 Received: from hqemgate14.nvidia.com ([216.228.121.143]:10894 "EHLO hqemgate14.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726047AbfFQRke (ORCPT ); Mon, 17 Jun 2019 13:40:34 -0400 Received: from hqpgpgate101.nvidia.com (Not Verified[216.228.121.13]) by hqemgate14.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Mon, 17 Jun 2019 10:40:33 -0700 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate101.nvidia.com (PGP Universal service); Mon, 17 Jun 2019 10:40:33 -0700 X-PGP-Universal: processed; by hqpgpgate101.nvidia.com on Mon, 17 Jun 2019 10:40:33 -0700 Received: from HQMAIL108.nvidia.com (172.18.146.13) by HQMAIL105.nvidia.com (172.20.187.12) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Mon, 17 Jun 2019 17:40:32 +0000 Received: from manikanta-bm2.nvidia.com (10.124.1.5) by HQMAIL108.nvidia.com (172.18.146.13) with Microsoft SMTP Server id 15.0.1473.3 via Frontend Transport; Mon, 17 Jun 2019 17:40:29 +0000 From: Manikanta Maddireddy To: , , , , , , CC: , , , Manikanta Maddireddy Subject: [PATCH V5 10/27] PCI: tegra: Disable AFI dynamic clock gating Date: Mon, 17 Jun 2019 23:09:35 +0530 Message-ID: <20190617173952.29363-11-mmaddireddy@nvidia.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190617173952.29363-1-mmaddireddy@nvidia.com> References: <20190617173952.29363-1-mmaddireddy@nvidia.com> X-NVConfidentiality: public MIME-Version: 1.0 Content-Type: text/plain DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1560793233; bh=iSl9/j8Vg+G/etQQQmqnwRBVQSJNn9s8EUSvlisTGPw=; h=X-PGP-Universal:From:To:CC:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:X-NVConfidentiality:MIME-Version: Content-Type; b=O5FVqlkbUE44/TLUKlW/pJAj+xQMEfcKGP5WzwufLyMY9zys7XgJFfRLVyOreDqHo /pveIhTyxlpq4jfssdxf2ikry9p6zagE+5NEGWwB+o4S15q3AmmEIDuHZG5A/du0T5 q9nxL1kHpRzYmvvzMY7u3Qpk8hgFJemKHOyWqBPrO0WjArvzH3n0aoVl40+Pqcy1Gn EQp6TrKs2X2MWuWeNO7SDI5Ro5JDSX9vCeBHT7MTw0iskMvzTOU8e6uaI++Ck83FKz f+QSBvEQjmGdoxp349ZA0CWePWm4bKajKs3fu5N5mr6DRYYfxuP+F0E2Mw+IwsqsuE b8HgSUm5bXfTw== Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Outstanding write counter in AFI is used to generate idle signal to dynamically gate the AFI clock. When there are 32 outstanding writes from AFI to memory, the outstanding write counter overflows and indicates that there are "0" outstanding write transactions. When memory controller is under heavy load, write completions to AFI gets delayed and AFI write counter overflows. This causes AFI clock gating even when there are outstanding transactions towards memory controller resulting in system hang. Disable dynamic clock gating of AFI clock to avoid system hang. CLKEN_OVERRIDE bit is not defined in Tegra20 and Tegra30, however programming this bit doesn't cause any side effects. Program this bit for all Tegra SoCs to avoid conditional check. Signed-off-by: Manikanta Maddireddy Acked-by: Thierry Reding --- V5: No change V4: No change V3: No change V2: No change drivers/pci/controller/pci-tegra.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/pci/controller/pci-tegra.c b/drivers/pci/controller/pci-tegra.c index 51691252ca10..ca02866fbbb4 100644 --- a/drivers/pci/controller/pci-tegra.c +++ b/drivers/pci/controller/pci-tegra.c @@ -95,7 +95,8 @@ #define AFI_MSI_EN_VEC7 0xa8 #define AFI_CONFIGURATION 0xac -#define AFI_CONFIGURATION_EN_FPCI (1 << 0) +#define AFI_CONFIGURATION_EN_FPCI (1 << 0) +#define AFI_CONFIGURATION_CLKEN_OVERRIDE (1 << 31) #define AFI_FPCI_ERROR_MASKS 0xb0 @@ -1065,9 +1066,10 @@ static void tegra_pcie_enable_controller(struct tegra_pcie *pcie) afi_writel(pcie, value, AFI_FUSE); } - /* finally enable PCIe */ + /* Disable AFI dynamic clock gating and enable PCIe */ value = afi_readl(pcie, AFI_CONFIGURATION); value |= AFI_CONFIGURATION_EN_FPCI; + value |= AFI_CONFIGURATION_CLKEN_OVERRIDE; afi_writel(pcie, value, AFI_CONFIGURATION); value = AFI_INTR_EN_INI_SLVERR | AFI_INTR_EN_INI_DECERR | -- 2.17.1